Mechanical Deformation-Assisted Alkaline Etching for High Performance Porous Silicon As a Lithium Storage Anode

Abstract

Development of lithium-ion batteries (LIBs) has led to the success of portable electronics and LIBs have gained a great deal of attention as power sources for emerging applications such as wearable devices, electric vehicles and robots. However, current LIBs reached technological limits for increasing their energy densities. To address this issue, much research effort has been devoted to finding high capacity electrode materials to replace currently used materials such as graphite anode in LIBs. Silicon (Si)-based anodes have attracted tremendous interest due to the huge theoretical capacity (3579 mAh g-1 and 2190 mAh cm-3) of Si. However, the huge volume expansion/contraction of Si during cycling lead to drastic capacity degradation. Recently, porous silicon materials have been revealed to alleviate the adverse effects arising from the large volume change of Si, thus showing outstanding electrochemical performances. However, their use in LIBs suffers from the complicated and limited routes for their synthesis. In this presentation, we represent a porous Si anode material prepared by a scalable and nontoxic chemical etching process. The resulting porous Si anode exhibited excellent cycle performance with a high discharge capacity as well as high dimensional stability. This material synthesis concept presented herein represents a means of improving the electrochemical properties of porous Si anode materials for use in commercial LIBs.